TiO2对铝硼硅酸盐玻璃结构和性能的影响

采用熔融法制备不同TiO2含量的RO(包括CaO、MgO)-Al2O3-SiO2-B2O3系玻璃。利用红外光谱技术研究TiO2对玻璃结构的影响,分别探讨了玻璃密度、化学稳定性和介电性能的变化规律。结果表明:少量TiO2的加入能够增大玻璃结构聚合度,过多的TiO2将使玻璃结构变得相对疏松;随着TiO2含量的增加,介电常数和介电损耗在1MHz频率下先减小后增大,玻璃析晶倾向和密度呈现增大的趋势,耐酸和耐碱失重比呈现先减小后增大的变化。     

Fluorochalcogenide glasses

A new variety of chalcogenide vitreous materials—fluorochalcogenide glasses—have been synthesized by the introduction of sodium, thallium, lead, manganese, and bismuth fluorides into the Ga₂S-GeS₂ system. These glasses are characterized by high glass transition temperatures (560–670 K), an optical transmittance up to 75% in the visible (from 0.48 μm) and IR (to 7.5 μm) spectral ranges, chemical durability in reactive acid media, low crystallization ability, and the stability of physicochemical and optical properties. Depending on the introduced fluoride, the glasses can be dielectrics, semiconductors, or ionic semiconductors. The spectral investigation of fluorochalcogenide glasses by using the X-ray emission, Raman, NMR, and EPR spectroscopy reveals the complex features of their structure. The metal cations form bonds with sulfur in different structural positions. The glass network providing the mobility of sodium ions is formed in sodium fluoride-containing glasses. The formation of groupings of the [≡Ga ← F-Ge≡] type is the main structural feature of fluorochalcogenide glasses.     

Fluorochalcogenide glasses

A new variety of chalcogenide vitreous materials—fluorochalcogenide glasses—have been synthesized by the introduction of sodium, thallium, lead, manganese, and bismuth fluorides into the Ga₂S-GeS₂ system. These glasses are characterized by high glass transition temperatures (560–670 K), an optical transmittance up to 75% in the visible (from 0.48 μm) and IR (to 7.5 μm) spectral ranges, chemical durability in reactive acid media, low crystallization ability, and the stability of physicochemical and optical properties. Depending on the introduced fluoride, the glasses can be dielectrics, semiconductors, or ionic semiconductors. The spectral investigation of fluorochalcogenide glasses by using the X-ray emission, Raman, NMR, and EPR spectroscopy reveals the complex features of their structure. The metal cations form bonds with sulfur in different structural positions. The glass network providing the mobility of sodium ions is formed in sodium fluoride-containing glasses. The formation of groupings of the [≡Ga ← F-Ge≡] type is the main structural feature of fluorochalcogenide glasses.     

氧化物添加剂对P2O5-ZnO-B2O3系低熔点玻璃物化性能的影响

作为绿色环保材料,无铅低熔点玻璃已经在电子元器件的封装和涂层等领域得到了广泛应用。以P2O5-ZnO-B2O3体系为基础玻璃,通过外加法研究氧化物添加剂(Fe2O3、MnO2、CuO、CeO2和Y2O3)对玻璃密度(ρ)、热膨胀系数(α)、特征温度(Tg和Td)及化学稳定性的影响。实验结果表明:使用适量的添加剂可以增大玻璃密度;除Y2O3外,其它添加剂提高玻璃的热膨胀系数;MnO2、CuO和Y2O3显著降低玻璃的特征温度,但Fe2O3和CeO2的影响较小;加入适量添加剂能显著改善玻璃的化学稳定性,其中加Y2O3的耐酸性最好,加CeO2的耐碱性最好。     

La^3＋掺杂无碱铝硼硅酸盐玻璃性能的研究

以La2O3-Al2O3-B2O3-SiO2玻璃系统为基础玻璃,用SiO2替代B2O3,通过DTA、IR等测试手段来研究其介电性能、热稳定性、化学稳定性及结构的变化。玻璃红外光谱分析表明,该系统玻璃结构与未掺La2O3玻璃的结构相同;玻璃的DTA曲线表明,随着SiO2替代B2O3含量的增加,玻璃的软化点增高,析晶温度升高,玻璃的热稳定性得到增强;同时随着替代量的增加,玻璃的耐酸耐碱性也得到提高;介电常数及介电损耗在SiO2/B2O3=2.7时出现极小值。     

TiO2对CaO-Al2O3-SiO2玻璃结构和性能的影响

采用DTA、IR方法研究TiO2对CaO-Al2O3-SiO2玻璃体系结构的影响。DTA分析结果表明,随氧化钛质量分数的变化,玻璃转变温度Tg呈现先升高后降低的趋势;析晶放热峰值温度Tp则逐渐降低。IR分析表明,少量的Ti4+的引入,有助于Al3+进入玻璃网络中。当氧化钛质量分数超过4%时,Ti4+以[TiO4]的形式进入玻璃网络,使网络结构加强;当氧化钛质量分数达到8%时,出现六配位状态的[TiO6]8-。随着氧化钛质量分数的增加,密度逐渐增大;化学稳定性先降低后升高,在一定范围内,引入TiO2能提高玻璃耐碱性。     

Relaxation mechanism in silver borate glasses

The electrical properties of silver ion conducting borate glasses are investigated by impedance spectroscopy in the temperature range 303–453 K. Impedance data are presented in the Nyquist plots. This representation allows the determination of the relaxation frequencies of the samples. The relaxation frequency follows an Arrhenius behavior. X-ray diffraction analysis shows that, due to the hygroscopic behavior of borate glasses, boric acid crystals are formed. In AgI-containing silver borate glasses, the β-AgI phase is formed and its structure mostly depends on the glass formation process, i.e., quenching or thermal treatment during melt quenching. In AgBr-containing glasses, a phase of AgBr is formed. The electrical properties of these glass systems can be described as a parallel RC circuit in which R represents the bulk resistance R _B and C represents the bulk geometric capacitance C _B of the sample. Impedance spectroscopy shows the Cole-Davidson type behavior. Published in Russian in Fizika i Khimiya Stekla. The text was submitted by the authors in English.     

Glass Formation in the PbO–GeO 2 System

The glass-forming region in the PbO–GeO2 system is studied. To increase the glass-forming limit in this system, the tempering rate of the samples has to be increased using special methodological practices. The dependence of the temperature of the synthesis of lead germanate glass on the PbO content is obtained. It is shown that the corrosion of alumina crucibles proceeded during the synthesis of lead germanate glass. The dependence of the thickness of the corroded layer of the alumina crucible wall on the time of the synthesis of the glass of the 55PbO · 45GeO2 composition, mol % at 900°С is obtained. It is proved that the obtained glass is X-ray amorphous within the whole range of compositions in the PbO–GeO2 system.     

Physical and Optical Properties of Borobismuthate Glasses Containing Vanadium Oxide

Glasses with compositions 20BaO · 10Bi2O3 · (70 – x)B2O3 · xV2O5 with x = 0, 0.2, 0.4, 0.6, 0.8 and 1 mol % were prepared by melt quenching technique. The amorphous nature was established by X-ray diffraction studies. Fourier transform infrared studies carried out for samples and it exhibit absorption bands for oxides in various structural units. Physical parameters viz., density, molar volume, molar refraction, dielectric constant, electro negativity, polaron radius and oxygen packing density were calculated. Theoretical optical basicity was estimated and is increasing with vanadium content shows increasing polarizability of samples. Metallization criterion decreases shows the metallic nature of samples, this implies that prepared glass samples can be used as amorphous semiconductors and could be used in electronics and memory switching devices. Using UV-vis spectra optical band gap energy (Eopt) calculated and is decreased from 2.998–2.453 eV, linear refractive index is measured from Eopt. Increase in Urbach energy (Eu) with vanadium component is observed.     

Structural analyses of RuO<Subscript>2</Subscript>–TiO<Subscript>2</Subscript>/Ti and IrO<Subscript>2</Subscript>–RuO<Subscript>2</Subscript>–TiO<Subscript>2</Subscript>/Ti anodes used in industrial chlor-alkali membrane processes

The morphology and composition of RuO₂–TiO₂/Ti and IrO₂–RuO₂–TiO₂/Ti anodes, which have been used for the production of chlorine for more than 10 years, were analyzed by various methods; such as high-resolution scanning electron microscopy, high-resolution Auger electron spectroscopy, electron probe X-ray emission microanalysis and X-ray diffraction analysis. Drastic changes in the surface morphology, including partial exfoliation of a small amount of the oxide layer and a reduction in the content of ruthenium species through dissolution, were observed for the RuO₂–TiO₂/Ti anode. For the IrO₂–RuO₂–TiO₂/Ti anode, on the other hand, there were moderate changes in the surface morphology and moderate dissolution of iridium and ruthenium species.     

Thermal,Electrical and Physical Properties of Glasses Based on Basaltic Rocks

Six glass compositions based on basaltic rocks and some industrial wastes, Batches were melted in an electric furnace at temperature 1400 °C for 2 h and then casted into rods and discs shapes. Many important techniques were used in the present study including X- ray fluorescence, thermal expansion, dielectric properties, indentation micro hardness, bending strength, density and chemical durability, The expansion coefficient in the temperature range 25–300 °C lies in the range between 48.78 to 59.76 × 10−7 /°C and the temperatures of Tg started at 668.79 °C and ranging between 668.79–632.34 °C and Ts started at 737 °C and lies in the range and 737–711.6 °C respectively. The lower expansion glasses have higher transition and softening temperatures and vice versa. Bending strength and Vickers micro hardness show a gradual decrease from 118 to 56 MPa and 6120–4020 MPa respectively with increasing cement dust content. In the same time the density increases from 2.79 to 2.96 g/cm3 by increasing cement dust content.     

Efficiency of decolorizing agents in the production of colorless commercial glasses from municipal glass cullet wastes

Se and Co oxides have been applied in the present work as decolorizing agents to produce colorless glass from colored municipal glass cullet that contains high iron oxide. The results obtained showed that the Fe ions present in the glassy matrix are largely in the form of Fe³⁺ ions, X-ray fluorescence (XRF), Electron Spin Resonance (ESR), UV-Visible, and Fourier Transformer Infrared (FTIR) analyses were used to investigate the prepared glasses. The results reveal that all samples have a strong ultraviolet charge transfer absorption consisting of two or three bands at the wavelengths regions 228–232, 274–278, and 304–309 nm. The transmission is related to both decolorizing agent and the content of municipal glass cullet. The ESR intensity of Fe³⁺ signal remains unchanged in all samples. The IR data illustrate the appearance of characteristic absorption bands for each group of glasses in the following ranges ∼470, 773–1049, 1382–1617, 2323, 2919, 3436 cm⁻¹ which can be attributed to Si-O-Si bending vibrations, Si-O-Si symmetric and anti-symmetric stretching of bridging oxygen, and stretching vibration of molecular water, respectively. The results indicate the ability to control the color of glasses by the addition of cullet wastes to commercial glass composition.     

Ionic conductivity of (As2Se3)1 ? x(AgHal)x (Hal = I, Br) nanocomposites

Nanocomposites based on chalcogenide glasses have been synthesized. A differential thermal analysis of (As₂Se₃)_{1 − x} (AgI) _x and (As₂Se₃)_{1 − x} (AgBr)x (0 ≤ x ≤ 0.5) samples has been performed. The size of nanofragments that undergo elementary structural transformations has been evaluated. The data obtained are in agreement with the evaluated sizes of X-ray coherent scattering regions. The electrical properties of the glasses under consideration have been studied using impedance spectroscopy in the temperature range 293–393 K. It has been demonstrated that the ionic component of the electrical conductivity dominates in glasses with a high content of silver halide.     

Na-Ti-Si氧化物Ti元素的化学状态分析

利用熔融方法制备了Na2O-TiO2-SiO2系统玻璃样品，用IR以及XPS等测试手段对系统玻璃样品结构进行了分析。结果表明：Na2O-SiO2-SiO2系统玻璃中Ti^4 离子可以部分地取代Si^4 离子的位置而以网络形成体的形式参与成玻。此外，通过对该系统玻璃的XPS钛元素的化学状态分析，认为该系统玻璃中Ti^4 离子存在[TiO4],[TiO6]等几种不同的微结构单元，并且随着玻璃中TiO2含量的增加，该系统玻璃中四方双锥结构的[TiO6]与正四面体结构的[TiO4]之比增大。     

Structure and properties of high Li2O-containing aluminophosphate glasses

The present study reports on the characterisation of the structure and properties of 50Li₂O·xAl₂O₃·(50 ? x)P₂O₅ glasses. The objective of the work has been to study the influence of the alumina content on the properties of lithium phosphate glasses, and the room temperature ionic conductivity in particular, with potential application as solid electrolytes in lithium secondary batteries. The glass formation domain has been also determined, proving that Al₂O₃ can be introduced only up to 5 mol%. The addition of alumina results in the increase of the glass transition temperature and decrease of the molar volume of the glasses. Furthermore, both chemical durability and room temperature conductivity increase as a function of the alumina content. The structure of the glasses has been followed by means of Fourier-transformed infrared spectroscopy (FTIR) and NMR spectroscopy, which has been used to establish the structure–properties relationship.     

Low-melting lead-free fluxes for enamels deposited on glass

Low-melting lead-free glass fluxes are developed to produce enamel for glass decoration. The glasses have the following parameters: CLTE (82–85) × 10⁻⁷ K⁻¹, chemical resistance to water less than 0.06%, and resistance to 2% solution of Na₂CO₃ less than 0.15%; fusibility 22–28 mm. __________ Translated from Steklo i Keramika, No. 6, pp. 29–31, June, 2006.     

Synthesis, structure, and dynamics of fluorine ions in glasses based on indium and bismuth trifluorides

The glass formation in the InF₃-BiF₃-BaF₂ system is investigated. It is shown that the introduction of BiF₃ into the glass composition brings about an increase in the chemical durability and the refractive index (up to 1.611 for the 35InF₃ · 30BiF₃ · 35BaF₂ glass). This makes it possible to consider these glasses as promising materials for cores of IR transparent optical fibers with a high aperture. The dynamics of fluorine ions in the temperature range 250–430 K and possible models for the structure of glasses containing indium, bismuth, and fluorine are analyzed.     

Synthesis, structure, and dynamics of fluorine ions in glasses based on indium and bismuth trifluorides

The glass formation in the InF₃-BiF₃-BaF₂ system is investigated. It is shown that the introduction of BiF₃ into the glass composition brings about an increase in the chemical durability and the refractive index (up to 1.611 for the 35InF₃ · 30BiF₃ · 35BaF₂ glass). This makes it possible to consider these glasses as promising materials for cores of IR transparent optical fibers with a high aperture. The dynamics of fluorine ions in the temperature range 250–430 K and possible models for the structure of glasses containing indium, bismuth, and fluorine are analyzed.     

Structure and crystallization of ZnO-B<Subscript>2</Subscript>O<Subscript>3</Subscript>-P<Subscript>2</Subscript>O<Subscript>5</Subscript> glasses

Structure and crystalline behavior of the ternary system ZnO-B₂O₃-P₂O₅ glasses were investigated by means of X-ray diffraction (XRD) and infrared Raman spectra. The research showed that number of the planar [BO₃] units increases with the increase of B₂O₃ content. When the B₂O₃ content is above ≥10 mol %, the relative content of planar [BO₃] units increases rapidly and causes weakening of the glass structure and decrease in the chemical stability. In the crystallized glasses the predominant crystal phase Zn₂P₂O₇ decreases with the increase of B₂O₃ content, while the crystal phase BPO₄ increases with it, which cause the declining of chemical stability and the decrease of thermal coefficients of expansion.     

Investigating the Intermediate Water Feature of Hydrated Titanium Containing Bioactive Glass

Intermediate water (IW) in hydrated bioactive glasses remains uninvestigated. We obtained titanium (Ti)-containing bioactive glasses (BGTs) (Ti at 5%, 7.5% and 10% of the glass system) using the sol–gel technique. Their thermal, physicochemical, and morphological properties, before and after Ti-doping, were analysed using DTA, XRD, FTIR, TEM, and SEM accessorised with EDAX, and size distribution and zeta potential surface charges were determined using a NanoZetasizer. The IW in hydrated BGTs was investigated by cooling and heating runs of DSC measurements. Moreover, the mode of death in an osteosarcoma cell line (MG63) was evaluated at different times of exposure to BGT discs. Ti doping had no remarkable effect on the thermal, physicochemical, and morphological properties of BGTs. However, the morphology, size, and charges of BGT nano-powders were slightly changed after inclusion of Ti compared with those of BGT0; for example, the particle size increased with increasing Ti content (from 4–5 to 7–28 nm). The IW content was enhanced in the presence of Ti. The mode of cell death revealed the effect of IW content on the proliferation of cells exposed to BGTs. These findings should help improve the biocompatibility of inorganic biomaterials.